In Camus' novel L'étranger / The Stranger, Meursault gets arrested for shooting "an Arab". During his pre-trial detention, his girlfriend Marie pays him a visit in prison and tries to give him some hope:
Elle a crié de nouveau : « Tu sortiras et on se mariera! » J'ai répondu : « Tu crois? » mais c'était surtout pour dire quelque chose. Elle a dit alors très vite et toujours très haut que oui, que je serais acquitté et qu'on prendrait encore des bains.
(Deuxième partie, II)
She shouted again, ‘You will get out and we'll get married!’ I answered, ‘You think so?’ but mainly to say something back. Then she quickly and still very loudly said yes and that I would be acquitted and that we would go swimming again.
Why is Marie so sure that Meursault would be acquitted? Is this conviction inspired by a two-tier justice system that existed in French Algeria? Based on what I read in the French and English Wikipedia articles, there was indeed discrimination, but these articles don't say whether a Frenchman would so easily get away with murdering an Algerian.
In addition to Marie's words, there's also the words by Meursault's lawyer near the start of Part II:
Mon affaire était délicate, mais il ne doutait pas du succès, si je lui faisait confiance.
My case was tricky, but he had no doubts about its success if I trusted him.
Since this is a murder case, it seems hard to believe Meursault would be acquitted without the existence of a two-tier justice system that treated French citizens much less strictly for crimes against committed against Algerians than, for example, the other way round.
Update regarding historical background: Capital punishment executed by guillotine existed in the French justice system until 1981; the last execution by guillotine was executed in 1977. In addition, we even know who the executioner in French Algeria was at the time of the publication of L'étranger, namely Maurice Meyssonnier.
For this question, I am looking for evidence that there was a two-tier justice system in Algeria that would allow a French murderer of an Algerian to escape a death sentence, and that Camus, who grew up in French Algeria, was aware of this.